Exploring attitudes toward COVID-19 vaccinations amongst healthcare workers at a national infectious disease center in Singapore-a cross-sectional study.

Objectives: Vaccine hesitancy among healthcare workers (HCWs) affects pandemic preparedness and public trust. This study used the theoretical domains framework to examine COVID-19 vaccination uptake, attitudes, and information sources among staff at Singapore's National Center for Infectious Diseases (NCID). Methods: A cross-sectional anonymous electronic survey was distributed to all 695 NCID employees between July and October 2022. Participation was voluntary, and 207 staff who agreed to participate completed and submitted the survey. The questionnaire captured demographics, vaccination history and timing, intentions for future boosters, information sources, and determinants mapped to domains such as knowledge, beliefs about consequences, social role, intentions, social influences, and sentiments. Results: Of 695 staff, 207 responded (29.8%); 99.5% of the respondents had received at least one COVID-19 vaccine dose and 84.5% reported yearly influenza vaccination. Government or official sources, local news, hospital teaching, and scientific journals were key information sources. Overall, 22.7% reported reservations about COVID-19 vaccines, mainly concerning short- and long-term side effects, perceived low efficacy, and underlying medical conditions. Conclusion: COVID-19 vaccine uptake among responding HCWs was high, but nearly one-quarter still reported reservations, mainly related to side effects, perceived efficacy, and pre-existing medical conditions. Trusted institutional and official information sources, together with workplace education, appear to support vaccine confidence. These findings suggest that future vaccination strategies for HCWs should prioritize clear risk communication, trusted education channels, and approaches that support sustained voluntary booster acceptance.